This application claims priority of Japanese Patent Application No. Hei 11-155480, Japanese Patent Application No. Hei 11-297433, Japanese Patent Application No. Hei 11-306033, and Japanese Patent Application No. Hei 11-367024. The complete disclosures of each of these Japanese patent applications are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a head-protecting airbag device provided with an airbag cover mounted on a body and covering a housed airbag. The airbag cover is pushed and opened by the airbag as the airbag inflates and expands, thus creating an opening for the airbag to protrude into the vehicle interior compartment.
2. Description of the Related Art
In the prior art, the airbag of the head-protecting airbag device is folded and housed from a pillar portion to a roof side rail portion at the peripheral edge of an opening, such as a door or window, on the interior side of a vehicle. An airbag cover conceals the airbag. The airbag is inflated to expand while opening the airbag cover (or a pillar garnish) when inflating gas flows into the airbag (as referred to in Unexamined Published Japanese Patent Application No. 9-315253).
The airbag cover of the head-protecting airbag device is firmly fixed on the body so as to prevent the airbag cover from being removed when pushed by the inflating airbag. Typically, the airbag cover is fixed on the body by mounting bolts, which are fastened on the body from the interior side of the vehicle.
When bolts are used, however, the head portions of the bolts are exposed to the vehicle compartment. From a design standpoint, it is necessary to hide the head portions of the bolts with caps or the like. Naturally, such caps have to be mounted so that the caps, too, are not removed when the airbag cover is opened. Thus, members for preventing the caps from being removed are indispensable in the prior art.
In summary, in order to fix the airbag cover on the body, not only are mounting bolts required, but caps and mounting members for the caps are also required. These requirements increase the number of parts and manufacturing steps, as well as the cost for mounting the airbag cover.
In order to avoid the requirements and problems of prior art, it is conceivable to provide clips on the back side of the airbag cover. These clips are retained on the body by inserting the clips into retaining holes formed in the body. By using these clips, the airbag cover is fixed on the body. These clips must be so firmly mounted on the body to prevent the airbag cover from being removed from the body when the airbag expands. If the clips are firmly mounted on the body, however, the airbag cover cannot be easily demounted, for maintenance or the like, from the body.
In order to solve the above-specified problems, the invention has a first object to provide a head-protecting airbag device with an airbag cover which can be firmly mounted in an easily demountable manner on the body without using any mounting bolt.
A second object of the invention is to provide a head-protecting airbag device with an airbag cover which can cover an airbag folded in a rear pillar portion, while maintaining an aesthetically pleasing appearance in the design of the rear pillar portion.
A third object of the invention is to provide a head-protecting airbag device with an airbag cover having a door portion which opens smoothly and quickly when the airbag is inflated to expand.
The first object of the invention can be achieved by a head-protecting airbag device comprising an airbag cover mounted on the body of a vehicle for covering a folded airbag. The vehicle body includes a retaining hole. The airbag cover includes an airbag cover body and a clip portion protruding from the back side of the airbag cover body. The clip portion is inserted into the retaining hole and retained by the body. The clip portion can establish two states: a first retaining state, in which the clip portion is so unextractably retained, when inserted into the retaining hole, that the clip portion cannot be removed from the retaining hole of the body by pulling the clip portion in an opposite direction to the inserting direction; and a second retaining state, in which the clip portion is inserted farther into the retaining hole than the position of the stated first retaining state, and is extractably retained to permit removal of the clip portion from the retaining hole of the body.
In the airbag cover of this head-protecting airbag device, the clip portion is inserted into the retaining hole to establish the first retaining state. Then, the clip portion is retained unextractably to the body so that the airbag cover is firmly mounted on the body. If the clip portion is pushed into the second retaining state, the clip portion can be simply extracted from the body.
In this head-protecting airbag device, therefore, the airbag cover can be firmly mounted in an easily demountable manner on the body without using any mounting bolt.
The stated clip portion may be constructed in the following manner. Specifically, the clip portion includes a plurality of pawl members adapted to be unextractably retained by the back side of a circumferential edge portion of the body defining the retaining hole. Each of these pawl members has a shrinking guide portion. From the first retaining position, the clip portion may be moved farther in the inserting direction so that the shrinking guide portion is guided by the retaining hole circumferential edge into the second retaining position, in which the pawl members are retained close to each other.
In the first retaining state, the clip portion is inserted into the retaining hole so that each pawl member is arranged on the body back side of the retaining hole circumferential edge. As a result, the airbag cover can be firmly mounted on the body.
When the airbag cover is to be demounted from the body, the clip portion is inserted together with the airbag cover farther in the inserting direction so as to take the second retaining state. Then, the shrinking guide portion is guided by the retaining hole circumferential edge on the body surface side to bring the pawls members close to each other, into a proximate (or narrow) state, in which the pawl members are retained. After placing the pawl members into the proximate state, the clip portion can be extracted from the retaining hole, without any interference with the circumferential edge of the retaining hole, by moving the airbag cover in an opposite direction to extract the clip portion from the retaining hole. As a result, the airbag cover can be simply demounted from the airbag cover.
The clip portion may be constructed of a core member and a cap as follows. The core member has rigidity, and includes a neck portion and a head portion. The neck portion protrudes from the back side of the airbag cover body. The head portion is arranged at the leading end of the neck portion, and has a larger width size than the neck portion. The cap is elastically deformable, and is mounted around the core member so as to cover the root portion side of the neck portion and the root portion side of the head portion. The cap includes first and second grooves and a fixedly retained portion. The first groove and the second groove of the cap are arranged, when the cap is mounted around the core member, so that the first groove is positioned on the leading end portion side of the neck portion, and the second groove is positioned on the root portion side of the neck portion. The inner circumference of the retaining hole can be fitted in the first groove and the second groove. The fixedly retained portion is arranged on the leading end side of the first groove, so that the fixedly retained portion is retained on the retaining hole circumferential edge on the body back side when the retaining hole is fitted in the first groove. The inner side face of the fixedly retained portion is set: such that a smaller clearance is present between the inner side face of the fixedly retained portion and the neck portion of the core member, when the cap is mounted around the core member, so that the fixedly retained portion can be deformed into the smaller clearance as the fixedly retained portion is pushed in the inserting direction into the retaining hole; such that the head portion of the core member cannot be extracted when the fixedly retained portion is retained in the first retaining position on the body back side of the retaining hole circumferential edge; and such that the head portion of the core member can be extracted from the cap when the inner circumferential portion of the retaining hole is arranged in the second groove. The inner side face of the cap on the root portion side of the fixedly retained portion is set: such that a larger clearance is left between the inner side face and the neck portion of the core member, when the cap is mounted around the core member, so that the clip portion can be pushed in the inserting direction until the inner circumferential portion of the retaining hole is arranged at the position of the second groove; and such that the head portion of the core member can be extracted from the cap when the inner circumferential portion of the retaining hole is arranged in the second groove.
In this airbag cover, the cap is mounted in advance around the core member from the root portion side of the neck portion to the root portion side of the head portion. Then, the fixedly retained portion of the cap is inserted into the retaining hole circumferential edge, so that the fixedly retained portion is positioned on the body back side. The inner side face of the fixedly retained portion is enabled, by the small clearance left between itself and the neck portion of the core member, to be pushed in the inserting direction into the retaining hole. As a result, the fixedly retained portion can be inserted so that the portion of the inner circumference of the retaining hole is seated in the first groove. When the inner circumferential portion of the retaining hole is seated in the first groove, moreover, the fixedly retained portion of the cap is retained on the body back side of the retaining hole circumferential edge so that the clip portion takes the first retaining state. During retention in the first retaining state, the inner side face of the fixedly retained portion is set so that the head portion of the core member cannot be extracted by pulling of the cap in a direction opposite to the insertion direction. Therefore, the fixedly retained portion of the cap is unextractably retained together with the core member on the retaining hole circumferential edge on the body back side. As a result, the airbag cover is firmly mounted on the body.
In order to demount the airbag cover from the body, the clip portion is pushed in the inserting direction so far as to arrange the inner circumferential portion of the retaining hole in the second groove of the cap. The larger clearance between the inner side face on the root portion side of the cap and the neck portion of the core member permits warping and makes it easy to arrange the inner circumferential portion of the retaining hole in the second groove, also known as the second retaining state. With the retaining hole circumferential edge retained in the second groove, the root portion side of the cap and the inner side face of the fixedly retained portion permits extraction of the head portion of the core member. Therefore, the core member can be simply extracted together with the airbag cover body. As a result, the airbag cover body can be easily demounted from the body. After demounting, the cap can be easily extracted from the retaining hole because the cap is elastically deformable.
The core member can be formed into a rod shape or a sheet shape. Moreover, the core member may be molded integrally with the airbag cover body.
Optionally, the cap desirably has a slit extending in the axial direction thereof from the leading end of the fixedly retained portion. The provision of a slit in the clip portion allows the cap to be mounted around the core member more easily. The slit may extend in the axial direction the entire length of the cap. If such a slit is present in the clip portion, the cap can be mounted around the core member in a radial direction, i.e., the direction perpendicular to the axial direction of the core member, by widening the slit.
The core member also may be formed so as to be interchangeable with a cap having a lower retaining force on the circumferential edge of the retaining hole. Interchanging for a cap having a low retaining force may be done, for example, if the airbag cover is to be used as an ordinary garnish that does not cover the airbag.
The airbag cover body may include an interchangeable base portion into which different clip portions can be mounted. For example, the interchangeable base portion can mount a clip portion having a lower retaining force on the circumferential edge of the retaining hole, so as to be demountable. In this case, the airbag cover can be used, if interchanged with a clip portion having a low retaining force, as an ordinary garnish.
The interchangeable base portion may have a retaining recess at a position different from the mounting position of the clip portion. The clip portion, which has a lower retaining force on the circumferential edge of the retaining hole, is mounted so as to be demountable in the retaining recess.
The second object of the invention is achieved by a head-protecting airbag device comprising an airbag cover, mounted on the body of a vehicle, for covering a folded airbag. The airbag is housed from a rear pillar portion to a roof side rail portion on the interior side of the vehicle. The airbag cover is a rear pillar garnish mounted on the body of the rear pillar portion. The rear pillar garnish includes a body portion and a door portion molded integrally. The body portion has a mounting seat capable of being mounted on the rear pillar portion of the body. The door portion is arranged on the upper end side of the garnish, and is opened by the airbag being inflated to expand. The portions of the door portion and the mounting seat of the body portion in the vicinity of the door portion are made of a thermoplastic elastomer. The remaining portion (i.e., the portion other than the portions of the door portion and the mounting seat of the body portion in the vicinity of the door portion) is made of a hard synthetic resin.
In the rear pillar garnish of this head-protecting airbag device, the door portion is pushed and opened by the airbag being inflated to expand, so as to protrude the airbag into the interior compartment of the vehicle.
The rear pillar garnish is an integral molding of the door portion and the body portion so that the door portion of the rear pillar garnish is not separately mounted. Therefore, the rear pillar garnish can be constructed without the parting line of the door portion being formed on the interior side of the garnish. In this manner, the appearance and design of the rear pillar portion are improved.
The mounting seat in the vicinity of the door portion is made of a thermoplastic elastomer. Therefore, even if the mounting seat is impacted when the door portion is pushed and opened as the airbag inflates to expand, the mounting seat is not broken. Rather, the impact is absorbed by the elasticity of the thermoplastic elastomer. The pushing force exerted by the inflating airbag properly acts on the door portion so that the door portion is smoothly opened.
In this head-protecting airbag device, therefore, the folded airbag can be arranged in the rear pillar portion while preventing deterioration in the appearance of the rear pillar portion. Additionally, the door portion can be smoothly opened when the airbag is inflated to expand.
The thermoplastic elastomer and the hard synthetic resin have a mutual compatibility to allow the door portion and the body portion to be closely bonded to each other.
Moreover, the mounting seat desirably has a clip portion capable of establishing first and second retaining states, as discussed above, so that the rear pillar garnish can be firmly mounted on the body in an easily demountable manner. As also discussed above, the clip portion may include a rigid core member and an elastically deformable cap.
A surface skin is desirably arranged on the interior surface side of the rear pillar garnish in the interior compartment of the vehicle to improve the appearance of the rear pillar portion.
The door portion can be arranged on the upper edge of the rear pillar garnish, and can have a hinge portion arranged on the lower edge side of the door portion so that the door portion is pushed and opened downward as the airbag inflates to expand. Alternatively, the door portion may have a portion arranged therearound to be ruptured so that the door portion is opened, when pushed by the airbag being inflated to expand, by rupturing the rupturable portion. In this rear pillar garnish, a portion of the airbag can cover the rear pillar portion.
The third object of the invention is achieved by a head-protecting airbag device comprising an airbag cover mounted on the body of a vehicle for covering a folded airbag. The airbag cover includes a body portion and a door portion. The door portion is pushed and opened by the airbag being inflated to expand. A regulating wall for separating or partitioning the airbag from the body portion is arranged at the boundary between the body portion and the door portion. In this head-protecting airbag device, when the airbag is inflated and expands, the regulating wall guides the pressure of the airbag towards the door portion to open the door smoothly and quickly.
The regulating wall may protrude from the side of the airbag cover and/or from the side of the body.
These and other objects, aspects and advantages of the invention will be apparent to those skilled in the art upon reading the specification and appended claims which, when read in conjunction with the accompanying drawings, explain the principles of this invention.